1. Field of Invention
The present invention relates to an ornamental frame of touch panel, and more particularly to an improved ornamental frame of a touch panel comprising a frame-shape ornamental layer disposed at the bottom surface of the touch panel for ornamenting and protecting the signal leads provided at the periphery edge of the touch panel.
2. Description of Related Arts
Recently, the touch panel is widely used in the mobile phones, the cameras, the satellitic navigators, and the other general consumer electric products, in order to improve the use interface and advance the input efficiency. Generally, the touch panel is transparent and arranged in front of the displays of these electric products, so as to enable the users to execute interacting inputs according to the instruction messages on the display, thereby the communication between human and the machine could be more user friendly and greatly improved. The typical touch panel comprises a capacitance type touch sensor insulatedly disposed between a top panel and a base panel, and signal leads disposed on the periphery edge of the stacked layers to transmit signals of the touch sensor to a signal processing circuit, and an ornamental frame disposed at the periphery edge of the touch panel, wherein the ornamental frame completely covers the signal leads on the periphery edge to protect the signal leads for ornamenting the panel. Conventionally, the ornamental frame is printed on the outside surface of the touch panel to form a thin color frame layer thereon.
Recently there is a trend to design the electric products in planar panel configuration, so the thin color frame layer is alternatively printed on the bottom surface of the upper panel to ensure that the touch panel having a smooth and flat surface after assembly. However, the printed thin color frame layer normally has a thickness of more than 15 μm, and even up to 200 μm. Hence, when the printed thin color frame layer is adhered between the upper panel and the lower panel, the adhesive glue always leaks near the edges of the thin color frame layer or has residual air bubbles therein, resulting that the optical character and the ornament are greatly damaged.
Besides, when the thin color frame layer is printed onto the bottom surface of the top panel, the upper ITO resistance film disposed on the upper portion of the bottom surface of the top panel must extend over the color frame layer to connect with the signal leads. However, the ITO resistance film only has a thickness of about 20 nm and is made of a material with poor flexibility, so that and the clearance difference between the thickness of the color frame layer and the bottom surface of the top panel will easily cause damages or fractures to the ITO resistance film when the ITO resistance film extending over the inner peripheral edge portion of the color frame layer, resulting in poor transmission signals. In order to avoid the aforesaid defectives, people skilled in the art replace the conventional printing means with a photo-resistance coating method to produce the ornamental frame, in which the photo-resistance film layer formed generally has a thickness of less than 1 μm, so that when it is arranged with the ITO resistance film, the ITO resistance film would not cause damages or fractures at the portions extending over the photo-resistance film layer. However, there are still a lot of shortcomings when the photo-resistance film layer is used in the ornamental frame. For example, as the light resistance film layer is very thin, it is very easy to be scraped that causes damages and translucent phenomenon during the manufacturing process of the touch panel. In addition, the current manufacturers produce aforesaid photo-resistance film by means of a wet-coating method, such as spin coating or slot coating, both of which use liquid form light resistance reagent to coat on the surface of the panel. However, when such light resistance reagent is coated onto the edges of the panel or the portions with grooves or holes thereon (such as holes for microphone or functional key), the light resistance liquid will always flow along the vertical faces of the edges and cause pollution, which is very hard to be cleaned up. As mentioned above, the conventional ornamental frame of the touch panel has a lot of shortcomings that needs to be improved and overcome.